Process for the manufacture of dyestuffs



United States Patent Ofiice Patented Oct. 16, 1962 3,658,991 PROCESS FORTim MANUFACTURE OF DYESTUFFS Walther Wolf, Georg lRiisch, and EberhardDegener, Leverknsen, Hehnut Klappert, Koln-Stammheim, and SiegfriedPetersen, Leverirusen, Germany, assignors to Farhenfabriken BayerAittiengesellschaft, Leverisusen, Germany, a corporation of Germany NoDrawing. Filed Oct. 4, 1960, Ser. No. 66,298 Claims priority,application Germany Mar. 18, 1957 Claims. (Cl. 269-313) This inventionrelates to novel dyestuffs and more particularly to macrocyclicphthalocyanine-like dyestuffs and to a process for their production andto intermediates for such dyestutfs and to methods for their production.

It is an object of the present invention to provide novel dyestuffs.Another object is to provide phthalocyaninelike dyestuffs in new shades.A further object is to provide dyestuiis which have excellent fastnessproperties. Other objects are to provide novel compounds which can beused for the production of said dyestuffs. Still another object is toprovide simple processes for the production of these compounds. Moreobjects will appear hereinafter.

These objects are obtained according to the present invention bysubjecting compounds which may be designated in one of their tautomericforms as optionally substituted 1 amino 3imino-4,7-dithia-4,5,6,7-tetrahydro isoindolenines, if desired, inmixture with other 3,4-disubstituted 2 amino 5 imino-pyrrolenines and/or 1- phenyl-3,5-diamino-triazol-(1,2,4), to a heat treatment insubstance or on a substrate preferably in the presence of heavy metalsor heavy metal compounds and preferably in the presence of reducingagents and in the presence of solvents, which can have reducingproperties. The 1- amino 3imino-4,7-dithia-4,5,6,7-tetrahydro-isoindolenines may be furthersubstituted in the 5- and 6-position for example 'by alkyl radicalspreferably lower alkyl radicals containing up to 4 carbon atoms or arylpreferably phenyl radicals.

These compounds can be designated in one of their theoretically possiblytautomeric forms by the following formula wherein R and R stand forhydrogen, lower alkyl or aryl radicals. In another tautomeric formulathese compounds can be described as 1,3-cliimino-4,7-'dithia-4,5,6,7-tetrahydro-isoindolines.

These compounds can be obtained by reacting the salts of1,2-dimercapto-1,Z-dicyanoethylene with organic compounds containing anexchangeable group on each of two carbon atoms which are in inc-positionin said organic compounds producing thel,2-dicyano-3,G-dithia-cyclohexenes-(l) which can be reacted withammonia to the 1 amino3-imino-4,7-dithia-4,5,6,7-tetrahydro-isoindolemnes.

The production of the 1,2 dicyano-3,6-dithia-cyclohexenes-( 1) can becarried out in the presence of inert solvents such as ethanol, acetone,dimethyl formamide, water, methyl glycol acetate, dioxan, pyridine orxylene. It is advantageous to operate in a dilute solution. The reactionis, moreover, preferably carried out at the lowest possibletemperatures. The optimum temperature range depends in each case on thereactivity of the exchangeable groups. In general, satisfactory resultsare attained by operating at temperatures within the range of between 0and 0., preferably 2080 C., but other temperatures may also be chosen.

Salts of the 1,2-dicyano-1,2-dimercapto ethylene are for example thealkali metal salts, the alkaline earth metal salts or the zinc or leadsalts.

Compounds having an exchangeable group on two carbon atoms which are inu-position are, for example, 1,2- dichloroethane, 1,2-dibromethane,1,2-dibromo-1-phenylethane, ethane-1,2-dimethane-sulfonate,propane-1,2-di-ptoluene-sulfonate or 1,2-dibromo-cyclohexane.

The cyclohexenes obtained can be substituted in the 4- and/or S-positionfor example by cyanoor aryl groups or by alkyl groups which can containhetero atoms such as 0. Furthermore these cyclohexenes can contain asecond double bond between the C-atoms in 4- and 5- position.

The reaction of the 1,2-dicyano-3,6-dithiacyclohexenes- (l) with ammoniais advantageously carried out in a solvent such as a low molecularweight alcohol, e.g. methanol or ethanol; or ethylene glycol or itsmonomethyl or ethyl ether, or formamide, preferably at a moderatetemperature. In general, temperatures within the range of 0-50 C.,preferably 15-30 C., are suitable. The reaction can generally beaccelerated at a somewhat elevated temperature and in the presence ofcatalysts. Suitable catalysts are, for example, metal hydroxides, metalamides and metal alcoholates, especially those of the alkali metals andheavy metals having the tendency to form complexes or the salts thereofsuch as Raney nickel, copper acetate or cobalt chloride. The reactionmay also be carried out in two steps by first reacting thel,2-dicyano-3,6-dithia-cyclohexene-(1) with alcohols such as methanol,ethanol or ethylene glycol, to form the corresponding isoindoleninessubstituted in the 3-position by two alkoxy groups. For this purpose itis advantageous to use an excess of alcohol and to operate at lowtemperatures, for example at 1050 C., preferably at 1530 C. Theresultant reaction products generally crystallise out. The reactionproducts thus obtained may be reacted with ammonia in a solvent, ifdesired.

An alternative of the process for the production of the l amino 3imino-4,7-dithia-4,5,6,7-tetrahydro-isoindolenines from the cyclohexenesconsists in first preparing from the1,2-dicyano-3,6-ditbia-cyclohexenes-( 1) the hydrogen halide additioncompounds by reacting the dinitriles with hydrogen halide e.g. hydrogenchloride or bromide and an alcohol in an inert solvent, or by theaddition of hydrogen halides in glacial acetic acid and subsequentlyreacting the halides thus obtained with ammonia.

The reaction of the cyclohexenes with the ammonia may be carried out,for example, by treating the 1,2-dicyano-3,G-dithia-cyclohexenesdirectly with liquid ammonia, if desired in the presence of the abovementioned catalysts. It is, however, also possible to react thedinitriles in such a manner that the dinitriles are first dissolvedrespectively dispersed in a solvent to which a catalyst may be added,and by then introducing gaseous ammonia. The reaction products may beworked up according to conventional processes.

The 4,7-dithia-4,5,6,7-tetrahydro-insoindolenines can, moreover, also beobtained in a similar manner to the Pinner imino ether synthesis byconversion of the corresponding dinitriles with hydrogen halide such ashydrogen chloride or hydrogen bromide and an alcohol in inert solvents,or in accordance with the process of French patent specification No.1,070,912 by conversion of dinitriles with hydrogen halide in glacialacetic acid and subsequent conversion of the reaction products thusobtained with ammonia.

For the production of the new dyestufis the l-amino-3-imino-4,7-dithia-4,5,6,7-tetrahydro-isoindolenines to be employed inaccordance with the invention can also be reacted under the samereaction conditions. in mixture with other 3,4-disubstitutedZ-amino-S-imino-pyrrolenines, such as 3,4-dialkylsubstituted2-amino-5-imino-pyrrolenines such as3,4-dimethyl-2-amino-S-imino-pyrrolenine or optionally substitutedl-amino-3-imino-isoindolenines such as the l-amino-3-imino-isoindolenineor/ and 1-phenyl-3,5-diaminotriazol-(1,2,4). In this event there areformed dyestufis having fastness properties similar to those produced bythe sole application of l-amino-3-imino-4,7-dithia-4,5,6,7-tetrahydro-isoindolenines.

. These dyestuffs can be designated in one of their tautomeric forms bythe following formula:

N N v v lei wherein A, B and C are radicals selected from the groupconsisting of lower alkyl,

and wherein D stands for a radical selected from the group consisting of2011.4 i s p s I a lower alkyl-substituted GET-CH2 s s V andphenyl-substituted CHrCHz S S and wherein Me is a heavy metal atomselected from the group consisting of nickel, cobalt and copper.

The dyestufis can be produced in substance or on a substrate. Theproduction of the dyestuffs in substance can be carried out by simpleheating to elevated temperatures, for example, 100200 -C in the presenceof a heavy metal compoundand preferably; in the presence of a weaklyreducing organic solvent. The formation of the dyestufis on fibres ortextile materials can be effected .for example, by neutral or acidsteaming of the l-amino- 3-imino-4,7-dithiaa,5,fl e hydroisoindol ine wich .mercaptoethylene and 5 grams of the sodium salt of diare-ifdesired, in admixture with the aforesaid compounds-brought on thematerials to be decorated in the presence of heavy metal compounds andin the presence of solvents which have preferably reducing properties attemperatures of about 100 C. or above 100 C.

Suitable heavy metal compounds are, for example, nickel acetate, nickelpropionate, nickel formiate, cobalt chloride, copper sulfate, copperphenylacetate and the copper complex compound of sarco'sine or ethylenediamine tetraacetic acid or other salts of the heavy metals.

As solvent there may be used for example alone or in mixture ethyleneglycol, propylene glycol, thiodiglycol, triisopropanolamine orpoly-glycols, and also acid amides, such as formamide orform-methylaniline. The production of the dyestuffs in substance isgenerally effected in closed vessels in order to enable the employmentof readily volatile solvents such as methanol or pyridine.

For theprocess according to the invention it is not necessary to use thel-amino-3-imino-4,7-dithia-4,5,6,7- tetrahydroisoindolenines in anisolated form; it is, in general, suflicient to work under conditions inwhich these compounds are intermediately formed. It is possible, forexample, to heat to elevated temperatures possibly substitutedl,2-dicyano-3,6-dithiacyclohexene-(1) in a solvent in'the presence ofheavy metal salts, and in the presence of small quantities of ammonia.There is intermediately formed 1-amino-3-imino 4,7 dithia 4,5 ,6,7-tetrahydroisoindolenine. Since a number of these molecules condense togive the phthalocyanine like dyestuif molecule, amomnia is freed in thiscondensation for a further reaction of the starting material. Thereaction can be carried out as Well in the presence of the aforementioned pyrrolenines or cyclic bis-amidines, in this case alsoeventually in the absence of additional ammonia since in the reactionammonia is formed.

Instead of 1,2-dicyano-3,ddithiacyclohexenes there can also be used thealcohol adducts easily obtainable therefrom, forexample, C H N O S whichmay be produced from 1,2-dicyano-3,6-dithiacyclohexene (C H N S byconversion with methanol in the presence of a little NaOCH at 2025 C.The adduct is colourless, crystallises in prisms and decomposes at 137C.

The formation of the final dyestufis proceeds via intermediate productswhich themselves have not yet dyestufi character but already contain themetal in complex combination. The synthesis of the dyestuffs may beinterrupted at any stage by first condensing in vitro l-amino-3-imino-4,7-dithia-4,5,6,7atetrahydroisoindolenine, formed in anisolated or intermediate form, with itself alone or with the aforesaidmixed components, in the presence of a heavy metal compound, preferablyunder mild conditions e.g. temperatures up to about C. and thencompleting the dyestufi synthesis with the intermediate compounds formedin the presence of an agent having reducing properties and in a solventpreferably at elevated temperature. The condensed dyestuff intermediateproducts can be isolated since they are soluble in water and methanolwith greater difliculty than the'arnino-iminodithia-tetrahydroisoindolenines.

The following examples are given for the purpose of illustrating theinvention, the parts by weight and the parts by volume being in theratio of grams to millilitres.

This application is a continuation-in-part application of our copendingapplications Serial Nos. 722,135, 722; 153, both now abandoned, and722,160, now US. Patent 2,941,292, died March 18,1958.

7 Example 1 ,95 grams of the disodium salt ofl,2-dicyano-l,2-dinsbutylnaphthalene-sulphonic acid are dissolved in 500millilitres of water. 40 millilitres of ethylene chloride are then addeddropwise at 50 60 C. and the mixture is vigorously stirred, at, thistemperature for two hours.

Upon cooling to 20 C. suction-filtration of the solid portions, Washingwith Water and drying, the resultant1,2-dicyano-3,G-dithiacyclohexene-(l) is isolated. Yield: 22 grams (M.P.132133 C.).

parts by weight of 1,2-dicyano-3,6-dithiacyclohexene-(l) are stirred in50 parts by weight of ethylene glycol at 70 C. for one hour whilepassing over NH the temperature is then slowly decreased to 20 C. andthe resultant brownish yellow solution is further saturated withammonia. The temperature is finally reduced to 0 C. to complete thecrystallisation of the formed base. By suction-filtration and washingwith acetone, 6.5 parts by weight of1-amino-3-imino-4,7-dithia-4,5,6,7-tetrahydro-isoindolenine areobtained.

4 parts by Weight of 1-amino-3-imino-4,7-dithia-4,5,6,7-tetrahydroisoindolenine or the tautomeric 1,3-diirnino-4,7-dithia-4,5,6,7-tetrahydroisoindoline and 1 part by weight of copperacetate are dissolved in 100 parts by weight of ethylene glycol. Acotton fabric is impregnated with this solution, the excess solutionremoved by squeezing and the fabric heated in a drying oven to 120l40 C.for 10 minutes. After boiling out with soap solution, there remains onthe cotton a strong, dull violet dyeing fast to light. The dyestuffobtained corresponds to the following formula:

H20CH2 s I s N N s \N I s H2O OH; 1 II N0uN Ivg z a. 2

\S l N I S s III HzC-Cfig Example 2 200 grams of the disodium salt of1,2-dicyano-1,2-di mercaptoethylene are dissolved in 800 millilitres ofmethanol and nitrogen is passed over. 200 grams of 1,2-dibromethane in100 millilitres of methanol are added drop- Wise with stirring and thetemperature is kept at 2025 C. by external cooling with water. Stirringis continued at 25 C. for half hour, the temperature is then slowlyraised and the reaction finally completed by boiling under reflux forone hour. Upon cooling with ice, a mixture of sodium bromide and1,2-dicyano-3,6-dithiacyclohexene- (1) is filtered off by suction whichis freed from sodium bromide by Washing with water. By concentration ofthe alcoholic reaction solution, further quantities of dinitrile may beprecipitated. A total of about 160 grams of thedicyano-dithia-cyclohexene are thus obtained. The crude product ispurified by recrystallisation from 70 percent alcohol, 50 percentacetone or acetic acid using charcoal.

4 parts by weight of 1,2-dicyano-3,6-dithia-cyclohexene- (1) are stirredwith 20 parts by weight of 3,3-n-methanolic ammonia at room temperaturefor one Week or allowed to stand. During this period the colourlesscrystals of the starting material disappear. At the same time, the 1,3-

diimino 4,7 dithia-4,5,6,7 tetrahydro-isoindoline (or 1-amino-3-imino-4,7-dithia-4,5,6,7-tetrahydro-isoindolenine) crystallisesout in deep yellow crystals.

The reaction product is filtered off by suction. The residue remainingin the solution may be isolated by evaporation of the solvent or it maybe precipitated as a red nitrate by stirring the filtrate in an aqueousammonium nitrate solution in acetic acid. The total yield isquantitative.

4 parts by weight of 1-amino-3-imino-4,7-dithia-4,5,6,7-tetrahydro-isoindolenine and 1 part by weight of copper acetate aredissolved in parts by weight of ethylene glycol. The solution is thenheated to 140 C. for a brief period, the temperature being kept above C.for about 10 minutes. The same octathiahexadecahydro copperphthalocyanine is thus substantially formed as that obtained on thefibre according to the process given in Example 1. By dilution of thecooled reaction mixture with methanol, suction-filtration of theprecipitate, Wash ing with methanol and drying there are obtained 3,4parts by weight of the dyestufi pigment having a purity of approximately95 percent.

Analysis.Cu, 8.3%; S, 33.5%; N, 15.55%.

The dyestufi may further be purified by redissolving from concentratedsulphuric acid. The colour of the solution in sulphuric acid is green.

Example 3 3 parts by weight of nickel acetate corresponding to (CH COO)Ni(H O) 8 parts by weight of 1,2-dicyano- 3,6-dithia-cyclohexene-( 1), 1part by weight of 7-n methanolic ammonia and 100 parts by Weight ofthiodiglycol are heated With stirring to -150 C. and this temperature ismaintained for 15 minutes. 1-amino-3-imino-4,7-dithia-4,5,6,7-tetrahydro-isoindolenine is obtained as an intermediatewhich is converted into the octathiahexadecahydro-nickel phthalocyanineat about IOU- C. Working up is carried out as described in Example 2. 8grams of a black pigment dyestuff are thus obtained, the formula ofwhich corresponds to the formula indicated in Example 1 wherein thecopper is substituted by nickel.

Analysis-S, 31.4%; N, 15.19%; Ni, 7.3%.

The dyestufi can further be purified by redissolving from sulphuric acidand at the same time brought into a form suitable for pigment printing.The colour of the solution in concentrated sulphuric acid is green.

Example 4 resp. 5 I .f'

and

Analysis.Ni, 8.6%; S, 24.0%; N, 17.10%. i The atomic ratio Ni:S:N istherefore approximately 1 :5 :8. By redissolution from concentratedsulphuric acid, the composition of the dyestutt is not changed.

Example 5 parts by weight of 1-amino-3-irnino-4,7-dithia-4,5,6,7-tetrahydro-isoindolenine and 2 parts by weight of copper acetate areheated to 65 C. for 40 minutes in 90 parts by weight of methanol. 10parts by weight of a brown dyestufi intermediate product are thusobtained which may readily be isolated by suction-filtration at roomtemperature. It contains 7% Cu, 29.4% Sand 16.23% N. The compound can berepresented by thefollowing formula:

11-12 percent of the starting material may be precipitated from thefiltrate as a red nitrate.

The dyestuff intermediatep roduct is soluble in thiodiglycol, diglycolmonomethyl ether and similar solvents and can be converted into theoctathia-hexadecahydro copper phthalocyanine by heating to temperaturesof above 100 C. For this purpose there are dissolved, for

product in 30 parts by weight of thiodiglycol and 5 parts by weight ofdiglycol monomethyl ether, the solution is mixed with 50 parts by weightof tragacanth thickening (65 21000) and 11 parts by volume of water. Thedyestutf paste is printed on cotton, pre-dried and the dyestufi isdeveloped by heating to 140 C, for 10 minutes. The conventionalafter-treatment follows and a deep violetblue print is obtained withvery good fastness properties.

example, 4 parts by weight of the dyestuif intermediate 3 parts byweight of a 16.5 percent'nickel, chloride solution and 44 parts byvolume of water Example 7 2 parts by weight ofl-amino-3-imino-4,7-dithia-4,5,6,7- tetrahydroisoindolenine and 6 partsby weight of a technical percent 1-amino-3-imino-isoindolenine arestirred in 15 parts by weight of a solvent mixture consisting of equalparts of formamide, dimethyl formamide, thiodiglycol, diglycolmonomethyl ether and triethanolamine, 10 parts by weight of a 11.9percent copper chloride solution, 40 parts by weight of tragacanththickening (65: 1000) and 27 parts by volume of Water to give a printingpaste. Fabric of cotton or artificial silkare printed with this printingpaste and the dyestuff is developed on the fibre, after usualpre-drying, by neutral steaming at C. for 10 minutes. By after-treatmentin conventional manner the-print is completed. A clear navy blue isobtained having very good fastness properties.

Example 8 6 parts by weight of 1-amino-3-imino-4,7-dithia-4,5,6,7-tetrahydroisoindolenine and 2 parts by weight of a technical 80percent 1-amino-3-imino-isoindolenine are stirred with 15 parts byWeight of the solvent mixture indicated in Example 7, 11 parts by weightof a 16.5 percent nickel chloride solution, 40 parts by Weight oftragacanth thickening (65:1000) and 26 parts by volume of Water to forma printing paste. Cotton and rayon fabrics are printed with thisprinting paste, pre-dried and the dyestutf is developed on the fibre byneutral steaming at 100- 105 C. for 10 minutes.

The material is after-treated in conventional manner. A neutral blackprint is obtained of very good fastness properties.

q Example "9 10 parts by weight of 1-amino-3-imino-4,7-dithia-4,5,6,7-'tetrahydro-isoindolenine and 35 parts by weight of1-amin'o-3-iinino-isoindolenine are stirred with 10 parts by weight ofcopper acetate 'in 200 parts by volume of thiodiglycol for 2 hours 'at atemperature of 65-70 C. in the dark. The brown-yellow solution obtainedcontains small amounts of dyestufi which is filtered off. A'metal-containing dy'estufif intermediate is obtained from the filtrateby introducing the filtrate into water, and filtering off theprecipitate; There, are obtained 27 parts by weight of a light brownpowder which contains 6.9% copper, 10.7% S and 18.35% N.

From this dyestuif intermediate there can be obtained a navy-bluedyestuff in substance or on fibers by treating this dyestufiintermediate in neutral or acid medium at higher temperatures with amildreducing agent or at lower temperatures with a stronger reducing agent.If the dyestuif intermediate is dissolved in methanol and a small amountof glacial acetic acid and then introduced into a cold aqueousdithionite solution the blue dyestuif is obtained immediately. If thedy'estufl intermediate is 65 dissolved ina solvent containing hydroxyethyl groups and is printed in the presence of atragacanththickener on acotton material, theblue dyestuff is obtained on this cotton materialafter pre-drying the printed material by a neutral or acid steamingperiod of 10 minutes at a temperature of 100-105 C.

Example 10 To a solution of 14 parts by Weight of, 1-amino-3-imino-4,7-dithia-4,5,6,7-tetrahydro-isoindolenii1e and 20 parts byweightof 1-phenyl-3,5-diamino triazol-(1,2,4) in 200 parts by volume ofethylene glycol is added dropwise a solution of parts by weight of ironchloride in 100 parts by volume of dimethyl formamide at 110 C. Themixture is then stirred for 8 hours at 1001l0 C. and then diluted with200 parts by volume of methanol. The precipitate is filtered off, washedwith methanol and water and dried. There are obtained 15.5 parts byweight of a brown dyestufr containing 7.3% iron and 20.2% sulfur. 10parts by Weight of this dyestutf are dissolved in 200 parts by volume ofpyridine, filtered and the filtrate is introduced into Water of 70 C.Thus, 7 parts by weight of a pure hemiporphyrazine are obtainedcontaining 7.8% iron and 19.2% sulfur. The dyestufi corresponds to thefollowing formula:

Similar dyestuffs are obtained if instead of the iron salt equivalentamounts of a copper or nickel salt are used.

Example 11 A mixture consisting of 20 parts by weight of Z-amino-5-imino-3,4-dimethyl-pyrrolenine nitrate, 20 parts by weight ofl-amino-3-imino-4,7-dithia-4,5,6,7-tetrahydroisoindolenine and 10 partsby weight of copper acetate are dissolved in 200 parts by volume ofethylene glycol and stirred for 1 hour at l10-l20 C. Thereafter thesolution is diluted with water, the precipitate filtered 0E and boiledwith diluted hydrochloric acid and diluted aqueous sodium hydroxidesolution and washed neutral. There are obtained 24 parts by weight of aviolet dyestuff. The color of the dyestuff in concentrated sulfuric acidis blue-green. The dyestuffs can be obtained unchanged from theconcentrated sulfuric acid. The dyestufi mixture contains the followingdyestuffs:

resp.

and

Corresponding nickel-containing dyestuffs are obtained if instead of thecopper acetate a corresponding amount of nickel acetate is used.

Example 12 14 parts by Weight of l-amino 3 imino 4,7-dithia-4,5,6,7-tetrahydro-isoindolenine, 7 parts by Weight of 1- amino-3imino-5 phenyl-isoindolenine, 5,4 parts by Weight of copper acetate,parts by volume of formamide and 60 parts by volume of ethylene glycolare heated to 120 C. for 1 hour while stirring. The further treatment isthe same as described in Example 11. Thus, 20 parts by weight of aviolet-black pigment are obtained which dissolves in sulfuric acid witha green color and which gives the following analysis: 49.75% C, 2.97% H,24.3% S.

This pigment contains the following compounds:

'and

Corresponding nickel-containing dyestuffs are obtained ifinstead of the.copper acetate a corresponding amount of nickel acetate is used.

The solution can be diluted with ethanol and the precipitate filteredoff, washed with ethanol and dried at 100 C. Yield 91 parts by weight.The dyestufi can be recrystallized from concentrated sulfuric acid. Itis reddish-violet'and the solution in sulfuric acid is yellow- 7 green.

Instead of N,N-dimethy1 aniline there can be also used N-ethyl anilineor benzyl cyanide and instead of the dichlorobenzene there can be alsoused trichloro benzene or chloro naphthalene.

Example 14 17 parts by weight of1,2,4-tricyano-3,6-dithia-cyclohexene-(l) are stirred into 100 parts byweight of a 36% hydrogen bromide solution in glacial acetic acid at atemperature of 20-25 C. V

Thereafter the mixture is diluted with 20 parts by volume of glacialacetic acid. -While the jstarting material dissolves, a 'salt isprecipitated which contains 56.75% of bromine resp. 57.5% of hydrogenbromide. The precipitate'is filtered oil and Washed with ether anddried. Yield: 50 parts by weight of a colorless hydrogen bromidereaction product.

43 parts by weight of this compound are introduced into 200 parts byvolume of anhydrous benzene and then added dropwise to 130 parts byvolume of a 3,3-methanolic ammonia solution at 2 0 C. Thereby 20 partsby weight of ammonium bromide precipitate which are filtered ofi.Fromthe filtrate" 20 parts by weight of a light brown powderare'pbtained upon distillation of the solvent in vacuo at 20-30 C. 7 V V16 parts by weight of this light brown powder are heated to 140 C. with2 parts by weight of copper acetate in 100 parts by volume of formamideand 100 parts by volume of ethylene glycol for minutes.

The dyestuffobtained is filtered off, washed with methanol, boiled withaqueous diluted hydrochloric acid, filtered ofi again, washed neutraland dried at 90-100 C. Thus, 8 parts by weight of a reddish-violetdyestnfi are obtained which dissolve in concentrated sulfuric acid withdark blue color. The dyestuff is a hexadecahydrooctathia-copperphthalocyanine tetracarbonic acid amide,

the formula of which corresponds to the formula indicated in Example 1,whereby each of the ring systems 14 is substituted in one of the 4- or5-positions by a CONH -group.

Example A mixture consisting of 1000 parts by volume of ethylene glycol,72 parts by weight of 1-amino-3-iminoisoindolenine, 278 parts by weightof l-amino-B-imino- 4,7-dithia-4,5,6,7-tetrahydro-isoindolenine, and 100parts by weight of copper acetate are heated to 1l0120 C. for 90 minuteswhile stirring. The pigment formed is filtered off, washed with waterand is boiled with diluted aqueous hydrochloric acid and diluted sodiumhydroxide solution, washed neutral and dried. Thus, 322 parts by weightof a violet-blue pigment are obtained con taining 9.3% copper, 16.06% Nand 27.8% S. The dyestuff corresponds to the formula:

Example 16 Example 17 A mixture consisting of 1000 parts by volume ofethylene glycol, 21 8 parts by weightof 1-amino-3-iminoisoindolenine, 93parts .by weight of 1-amino-3-imino-4,7-dithia-4,5,6,7-tetrahydro-isoindolenine and parts by weight ofcopper acetate are treated-as described in Example 15. Thus, 275 parts'by weight of a navy-blue pigment are obtained which contains 10.8%copper, 18.15% N and.11.l% S. The dyestufi is a dithia-tetra- 13hydro'copper phthalocyanine having the following formula:

A corresponding nickel-containing dyestufi is obtained if instead of thecopper acetate a corresponding amount of nickel acetate is used.

Example 18 Example 19 To a mixture consisting of 84.4 parts by weight of1-amino-3-imino-isoindolenine, 27.7 parts by weight of l-amino-B-imino4,7-dithia 4,5,6,7 tetrahydro-isoindolenine in 375 parts by volume ofmethanol a solution of 30 parts by weight of copper acetate dissolved in150 parts by volume of a ammonia solution is added. This mixture isstirred at 45 C. for about 1620 hours. Then the solid parts are filteredoff, washed with methanol and dried. Thus, 102 parts by weight of abrownishyellow powder are obtained which dissolve in diglycol monomethylether or in pyridine with yellow-brown color.

.If the brownish-yellow powder is dissolved in diglycol monomethyl etherand an aqueous solution of sodium dithionit added, a reddish-bluecopper-containing pigment is precipitated at room temperature. The samedyestuff is obtained if the brownish-yellow powder is heated withdimethyl aniline for minutes to the boil.

The solution of the brownish-yellow powder in diglycol monomethyl ether,thio diglycol or similar solvents can be used for obtainingdeep-violet-blue prints on native or regenerated cellulose by the methoddescribed in Example 9.

Example 18.6 parts by weight of the disodium salt of the 1,2-dicyano-1,2-dimercapto ethylene, 9.9 parts by weight of1,2-dichloroethane and 100 parts by volume of absolute alcohol areheated in a closed vessel for 6 hours to 100 C. The precipitate obtainedis filtered off and extracted with chloroform. The alcohol extract isintroduced into the fourfold amount of water and this mixture thenextracted several times with chloroform. The chloroform extracts arewashed with water, treated with active carbon and dried with sodiumsulfate. Upon evaporating the solvent 13 parts by weight ofl,2-dicyano-3,6-dithia-cyclohexene-(l) is obtained which is purified asdescribed in Example 2.

50 parts by weight of 1,2-dicyano-3,6-dithiacyclohexene-( 1) are stirredwith 100 parts by weight of anhydrous methanol and, while passing overNH 20 parts by weight of a 15 percent methanolic sodium methylatesolution are added dropwise at 20-25 C. The exothermic heat iscompensated by cooling. A colourless intermediate product crystallisesout which dissolves again with progressive reaction. This colourlessintermediate product is1-amino-3,3-dimethoxy-4,7-dithia-4,5,6,7-tetrahydro-isoindolenine.

The resultant crystal slurry is filtered oif by suction at 0 C. after20-24 hours and washed with a mixture of equal parts of methanol andacetone. 45 parts by weight of pure1,3-diimino-4,7-dithia-4,5,6,7-tetrahydro-isoindoline are thus obtained.Further portions of the base may be precipitated as a red nitrate asindicated in Example 2.

A compound similar to the l-amino-3,3-dimethoxy-4,7dithia-4,5,6,7-tetrahydro-isoindolenine can be obtained as follows:

10 parts by weight of sodium methylate are dissolved in 400 parts byvolume of ethylene glycol and then slowly introduced 200 parts by weightof l,2-dicyano-3,6-dithiacyclohexene-(l) at 25-35" C. Thereafter acetoneis added, the precipitate filtered off and washed with acetone. Thus 328parts by weight of l-amino-3,3-bis(,B'-hydroxy ethoxy)4,7-dithia-4,5,6,7-tetrahydro-isoindolenine are obtained. This compoundcan be used in the same manner as the corresponding dimethoxy compound.If this compound is boiled in acetic acid anhydride an acetyl derivativeis obtained having the formula C H N O S Melting point 209-210 C.

Example 21 297 parts by weight of the disodium salt of 1,2-dicyano-1,2-dimercapto ethylene are dissolved in a mixture of 300 parts of waterand 300 parts by weight of methanol. Thereafter parts by volume ofethylenebromide are added at 10 C. The mixture is stirred for 5 hours at25 C. Thereafter the precipitate is filtered off, washed with a 50percent methanol and dried. Thus parts by weight of1,Z-dicyano-3,6-dithia-cyclohexene-(1) are obtained.

40 parts by weight of 1,2-dicyauo-3,6-dithiacyclohexene-(l) are stirredat 2030 with 325 parts by weight of 20 percent hydrogen bromide inglacial acetic acid. Whilst the starting material dissolves, theexothermic heat is compensated by cooling. After a few hours the yellowhydrogen bromide adduct crystallises out. The precipitation is completedby cooling to 0-5 C. It can readily be isolated by suction-filtration,and washing with ether or benzine. The resultant 94 parts by weight ofthe intermediate product are introduced into a mixture of parts byvolume of benzene and 150 parts by volume of 7,8-n-methanolic ammonia,the temperature being maintained at 2025 C. by cooling. The reaction iscompleted by heating the mixture to 30-35 C. for a brief period, theice-cold precipitated ammonium bromide (55 parts by weight) is thenfiltered oil by suction and the reddish brown filtrate brought todryness under a vacuum at 3035 C. 54 parts by weight of a brownish redpowder are thus obtained having the approximate formula (C H N S +HBr.

Example 22 18.6 grams of the disodium salt of1,2-dicyano-1,2-dimercaptoethylene are suspended in 100 millilitres ofabsolute alcohol and 20 grams of 1,2-dibromopropane in 50 millilitres ofalcohol are added dropwise with cooling and passing through nitrogen.After boiling under reflux for 3 hours, the solution is cooled andpoured into four times its volume of water. 11 grams of 4-methyl-1,2dicyano-3,6-dithia-cyclohexene-(l) are filtered oif by suction. Uponcrystallisation form 70 percent alcohol and decolouring with charcoalcolourless crystals are obtained of M.P. 87-88 C.

5 parts by weight of 1,2-dicyano-4-methyl-3,6-dithiacyclohexene-(l) aresuspended in 14 parts by weight of methanol, the mixture is saturated bypassing over NH and 3 parts by weight of a 15 percent methanolic sodiummethylate solution are simultaneously introduced dropwise. Thetemperature is kept at 20-25 C. by cooling.

4.5 parts by weight of the yellow 1,3-dirnino--rnethyl-4,7-dithia-4,5,'6,7-tetrahydro isoindoline are thus obtained. Example 2326.4 grams of 1,2-dibrorno-l-phenylethane are added to a suspension of'21 grams of the disodium salt of 1,Z-dicyano-1,2-dirnercaptoethylene in150 millilitres of absolute alcohol. The mixture is first stirred at 40C. for 30 minutes while passing through nitrogen and then heated underreflux for 90 minutes. After cooling, the precipitate formed is filteredoff by suction and extracted with chloroform. By evaporation of thechloroform and concentration of the alcoholic reaction solutions, atotal of 10.2 grams of 4-phenyl-1,2-dicyano-3,6-dithia-cyclohexene-(l)are obtained. MP. e129130'C.

5 grams of 1,2-dicyano-4-phenyl-3,6-dithiacyclohexene-(l) are stirred at20-25 C. with 1 8 grams of a 37 percent solution of hydrogen bromide inglacial acetic acid. The starting material dissolves. After some timethe hydrogen bromide adduct precipitates being obtained after somestirring in the form of'a crystal slurry. After 20-70 hours thecrystallisation is completed by the addition of ether, the cold reactionproduct is filtered off by suction, washed with ether and dried over.potassium hydroxide-in vacuo.

The product thus obtained is introduced with cooling into a mixture of40 millilitres of anhydrous benzene and 40 millilitres of 3-n-methanolicammonia, the mixture is warmed to 35 C. for a few minutes, filtered offby suction at 15-20" C. and washed with a mixture of benzene andmethanol (1:1). 7 stantially of approximately 5 grams of NH Br. The

filtrates contain about 6 grams of the brown basic hydrobromide ofl-amino-3-imino-5-phenyl-4,7-dithia-4,5,6,7- tetrahydro-isoindoleninewhich is isolated by distilling oi the solvent in vacuo at 2030 C.

7 Example 24 15 0 parts by weight of NaS-CSCN+ 3 (CH NCHO concentratedand then poured into water. The oil obtained is taken up in ether. Theether solution is then washed with water and'dried with sodium sulfate.Upon evaporating the solvent 10 parts by weight of 4-methoxy methyl 1,2dicyano 3,6 --dithia cyclohexene (1) are obtained as an oil from whichyellow crystals are obtained upon cooling.

Example 26 8 parts by weight of l,Z-dicyano-3,6-dithiacyclohexene-(l)and 4 parts by weight of soda rnide are dissolved in 40 parts by weightof formamide. After hours the dark yellow reaction mixture is stirred ina solution of 8 parts by weight of ammonium nitrate and 24 parts byweight of acetic acid in 400 parts by weight of water,

. the precipitated red nitrate is filtered oif by suction and washedwith water and acetone. 6.5 parts by weight of C H N S +HNO are thusobtained corresponding to 55 percent of the theoretical yield.

Example 27 Into a solution consisting of 186 parts by weight of thedisodium salt of 1,2-dicyano-1,2-dimercapto ethylene, 10 parts by weightof the sodium salt of dibutylnaphthaline sulfonic acid and 1 part byweight of potassiumborhydride dissolved in 1500 parts of water and 750parts by volume of dimet-hylformamide, there are added dropwise within15 minutes 150 .parts by weight of 2,3 dichloropropionitrile at 2550 0.Upon about further 30 minutes the reaction product begins tocrystallize. Upon cooling off the precipitate is filtered ofi, washedwith water and dried. Thus 135 --parts by weight of the The filterresidue consists sub-- (obtained by the process described by Biihr and ISchleitzer in Chernische Berichte, vol. 88, page 1771) are dissolved in200 parts of water. After 20 hours, the precipitated sulfur is filteredoff. To the filtrate there are added 22 parts by volume ofethylenebromide and 100 parts by volume of methanol. This mixture isstirred for 7 hours at 20-25 C. Thereafter the precipitate is filteredoff, washed with a' percent methanol and dried. Thus31 parts by weightof l,2-dicyano- 3,6-dithiacyclohexene-( l) are obtained.

Instead of themethanohthere can be-used also an- 7 other solvent whichis miscible with water, such as dimethylformamide or dioxane. If theprocess is carried out in the absence ofoxygen, a very pure nearly whiteproduct is obtained. jlfthe process is carried out in the presence ofoxygen similar pure products can be obtained, if the process is carriedout in the presence of an antioxydant such as potassium boranate.

. 7 Example 25 V g 7 To. a solution of 20 parts'by weight of thedisodium salt of 1,2-dicyano-1,2-dimercapto ethylene in 130 partsby'volume of absolute ethanol there are added dropwise 23 parts byweight of 2,3-dibromo-1-methoxypropan dissolved in. 40 parts byvolume'of ethanol at 30 C., while stirring and passing through nitrogen.Thereafter the mixture is stirred for 30 minutes at 40 C. and thenheated under reflux for 90 minutes. Upon cooling the sodium'bromideiOImed is filtered ofi, the solution is nearly colourless1,2,4-tricyano-3,6-dithia-cyclohexene-( 1) are obtained. The product canbe recrystallized from cblorobenzene. The pure, colourless productdissolves with yellow colour in concentrated sulfuric acid or dilutedaqueous ammonia.

Example 28 10 parts by weight of 1-amino-3 imino-4,7-dithia-4,S,6,7-tetrahydro-isoindolenine and 2 parts by weight of copper acetate areheated to 65 C. for 40 minutes, in parts by weight of methanol. 10 partsby weight of abrown dyestufi intermediate product are thus obtainedwhich may readily be isolated by suction-filtration at room temperature.It contains 7% Cu,'29.4% S and 16.23% N.

The dyestufl intermediate product is soluble in thiodiglycol, diglycolmonomethyl ether and similar solvents and can be converted into theoctathia hexadecahydro copper phthalocyanine by heating to temperaturesof above C.

Weclaim:

.1. A tautomen'c compound mula having the following forherein A, B and Care each selected from the group consisting of lower alkyl,

011-011 GHr-CH:

HO OH, 8 s a lower alkyl-substituted 1 i QHOH no OH 17 18phenyl-substituted 3. A compound which in one of its tautomeric forms isCH CH of the following formula HO OH s NH 1120 olower alkyl-substitutedl V,

/oH:-Cga H2 s s l S N H: and phenypsubstimted l0 4. A compound which inone of its tautomeric forms is CHPCH: of the following formula s 00mOCH; H2O o-o and wherein D stands for a member selected from the ll 1group consisting of 0 11,0 I CH:CH2 S NH: 5. A compound which in one ofits tautomeric forms is lower alkyl-substituted of the formula S o s sand phenyl-substituted R I N CHr-CH: S S l NH: and wherein Me is a heavymetal atom selected f the whereby R represents a member selected fromthe group group consisting of nickel, cobalt and coppen consisting ofhydrogen, lower alkyl and phenyl. hf gsfifi z whlch m one of Itstautomenc forms 18 References Cited in the file of this patent UNITEDSTATES PATENTS 2,683,643 Baumann et a1 July 13, 1954 s O 2,739,151 Roschet a1 Mar. 20, 1956 2,739,155 Rosch et a1 Mar. 20, 1956 R I 2,752,346Rosch et a1. June 26, 1956 s OTHER REFERENCES 1 Lubs: Chemistry ofSynthetic Dyes and Pigments, pages 580-581 (1956). whereby X and Y standfor a member selected from the G. Bahr et al.: Chemische Berichte, vol.90, pages 43 8- group consisting of methoxy, ethoxy and fi-hydroxyethoxy443 (1957). groups and whereby R represents a member selected from G.Bahr et al.: Chemical Abstracts, 1957, vol. 51, col.

the group consisting of hydrogen, lower alkyl and phenyl. 45 87e,

1. A TAUTOMERIC COMPOUND HAVING THE FOLLOWING FORMULA
 3. A COMPOUNDWHICH IN ONE OF ITS TAUTOMERIC FORMS IS OF THE FOLLOWING FORMULA